The bottling or filling of containers, bottles or cans, in a "bottling plant" involves the processing of the individual containers into and through a multi-wrap machine. This machine receives the containers, groups them in two lines and forms successive groups of six or eight containers, and wraps the groups in succession to form what is referred to in the market as a "six pack" or "eight pack" of the product. The output of the wrap machine is delivered to a tray packer in which either four or three of either the six or eight packs, respectively, are placed in a carton, referred to as a tray, having shallow sides and a bottom (usually open at the top). Once in the tray, the packages are placed on pallets and handled in the distribution or warehousing system of the bottler. The bottling plant normally produces the packs (six or eight) on two multi-wrap machines to feed a single tray packer in a production line flow and without interruption.